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c16af17927
Currently it produces following output with duplicate events when
--for-each-cgroup option is used. It seems perf stat adds them when
it handles default events but didn't copy some fields in evsel__clone().
$ sudo perf stat -a --for-each-cgroup / true
Performance counter stats for 'system wide':
8,440,165 duration_time /
8,439,895 duration_time /
8,440,015 duration_time /
8,440,024 duration_time /
8,440,075 duration_time /
8,440,095 duration_time /
330 context-switches / # 679.4 cs/sec cs_per_second
485.69 msec cpu-clock / # 57.5 CPUs CPUs_utilized
70 cpu-migrations / # 144.1 migrations/sec migrations_per_second
71 page-faults / # 146.2 faults/sec page_faults_per_second
12,183,711 branch-misses / # 10.9 % branch_miss_rate (5.15%)
111,981,297 branches / (5.15%)
95,844,809 branches / # 197.3 M/sec branch_frequency (35.49%)
65,611,429 cpu-cycles / # 0.1 GHz cycles_frequency (98.32%)
24,170,987 cpu-cycles / (95.12%)
18,552,509 instructions / # 0.8 instructions insn_per_cycle (95.12%)
22,405,293 cpu-cycles / (64.78%)
6,840,383 stalled-cycles-frontend / # 0.31 frontend_cycles_idle (64.78%)
<not counted> cpu-cycles /
<not supported> stalled-cycles-backend / # nan backend_cycles_idle
<not supported> stalled-cycles-backend / # nan stalled_cycles_per_instruction
<not supported> instructions /
<not supported> stalled-cycles-frontend /
0.006546057 seconds time elapsed
Some events weren't counted. Try disabling the NMI watchdog:
echo 0 > /proc/sys/kernel/nmi_watchdog
perf stat ...
echo 1 > /proc/sys/kernel/nmi_watchdog
But I'm worrying about opening same events multiple times. Probably due
to grouping, but I'm not sure if it's beneficial in the end. Without
duplication, it seems it won't cause multiplexing (assuming no other
users at the same time).
Fixes: a3248b5b54 ("perf jevents: Add metric DefaultShowEvents")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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